The present invention relates to expellant holders for expendable substances such as lipsticks, lip balms, deodorant sticks, anti-perspirant sticks, glue sticks and other applicative cosmetics.
The prior art holder for expendable substances and the likes generally comprises a cylinder having a rotatable member disposed at its bottom end. A mass of expendable substance such as lipstick is received inside a receiving cup and is normally disposed within the cylinder. Rotation of the rotatable member relative to the cylinder causes a mechanism inside the cylinder to advance the expendable mass longitudinally away from the rotating member such that the mass is exposed above the cylinder. In this manner, the exposed portion of the mass is available for application.
The problem encountered with the prior art expellant holder is that the expendable mass is only secured to the receiving cup by the frictional force acting on the contact surfaces between the receiving cup and the expendable mass, as disclosed in U.S. Pat. No. 3,9991,777 to Powers et al. and U.S. Pat. No. 3,214,012 to Mack. To increase the contact surface areas, longitudinally extending internal ribs are added on the receiving cup as disclosed in U.S. Pat. No. 3,175,680 to Fuglsang-Madsen et al. and U.S. Pat. No. 4,579,134 to Moore.
It has been found that the frictional force between the contacting surfaces is insufficient to retain the expendable mass in the receiving cup when the expellant holder is exposed to sudden shocks, e.g., when the holder is dropped on its top end. Such shocks may dislodge the expendable mass from the receiving cup and the expellant holder is rendered inoperable. This problem is magnified when the expendable substance disposed in the receiving cup is relatively heavy, e.g., deodorant sticks. While the internal ribs may offer additional frictional resistance against shocks, they do not provide a different type of resistance. Additionally, due to the aesthetic aspects of the expellant holders, it is necessary that any additional resisting force does not disturb the aesthetic appearance of the expellant holders.
Thus, there continues to be a need in the art for an expellant holder including lipstick holder that is capable of resisting forced separation of the expendable mass from the holder caused by mechanical shocks.